Purpose of review: The diagnosis of intrinsic sphincter deficiency became important about 20 years ago when it influenced the choice of operative procedure for women with stress urinary incontinence. However, it was ill-defined and diagnosed by a variety of techniques.
The contemporary surgical treatment of urinary stress incontinence is by suburethral sling; so this review addresses three questions: is it still important to identify intrinsic sphincter deficiency prior to surgical intervention for stress incontinence? What techniques are available to do so? How robust are these measurements?
Recent findings: There is some evidence that women with intrinsic sphincter deficiency have a poorer outcome if they are treated by a transobturator tape compared with a tension-free vaginal tape or a pubovaginal sling. Intrinsic sphincter deficiency continues to be mainly identified by low urethral closure pressures or low abdominal leak point pressures or both but the methodology is variable. There have been some attempts at using ultrasound to identify intrinsic sphincter deficiency but without any definite conclusions.
Summary: Intrinsic sphincter deficiency is an imprecise diagnosis, which continues to be defined by a low pressure urethra. This can be measured in different ways but there is poor standardization of the tests to do so. Intrinsic sphincter deficiency appears to be clinically important but the full implications of this diagnosis will remain unknown until this imprecision is addressed.